c30ad90274f3ff2d58a21952395167920b5361ad
[libav.git] / libavcodec / mimic.c
1 /*
2 * Copyright (C) 2005 Ole André Vadla Ravnås <oleavr@gmail.com>
3 * Copyright (C) 2008 Ramiro Polla <ramiro@lisha.ufsc.br>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <stdlib.h>
23 #include <string.h>
24 #include <stdint.h>
25
26 #include "avcodec.h"
27 #include "bitstream.h"
28 #include "dsputil.h"
29
30 #define MIMIC_HEADER_SIZE 20
31
32 typedef struct {
33 AVCodecContext *avctx;
34
35 int num_vblocks[3];
36 int num_hblocks[3];
37
38 uint8_t *swap_buf;
39 int swap_buf_size;
40
41 int cur_index;
42 int prev_index;
43
44 AVFrame buf_ptrs [16];
45 AVPicture flipped_ptrs[16];
46
47 DECLARE_ALIGNED_16(DCTELEM, dct_block[64]);
48
49 GetBitContext gb;
50 ScanTable scantable;
51 DSPContext dsp;
52 VLC vlc;
53 } MimicContext;
54
55 static const uint32_t huffcodes[] = {
56 0x0000000a, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
57 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
58 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x0000000b,
59 0x0000001b, 0x00000038, 0x00000078, 0x00000079, 0x0000007a, 0x000000f9,
60 0x000000fa, 0x000003fb, 0x000007f8, 0x000007f9, 0x000007fa, 0x000007fb,
61 0x00000ff8, 0x00000ff9, 0x00000001, 0x00000039, 0x0000007b, 0x000000fb,
62 0x000001f8, 0x000001f9, 0x00000ffa, 0x00000ffb, 0x00001ff8, 0x00001ff9,
63 0x00001ffa, 0x00001ffb, 0x00003ff8, 0x00003ff9, 0x00003ffa, 0x00000000,
64 0x00000004, 0x0000003a, 0x000001fa, 0x00003ffb, 0x00007ff8, 0x00007ff9,
65 0x00007ffa, 0x00007ffb, 0x0000fff8, 0x0000fff9, 0x0000fffa, 0x0000fffb,
66 0x0001fff8, 0x0001fff9, 0x0001fffa, 0x00000000, 0x0000000c, 0x000000f8,
67 0x000001fb, 0x0001fffb, 0x0003fff8, 0x0003fff9, 0x0003fffa, 0x0003fffb,
68 0x0007fff8, 0x0007fff9, 0x0007fffa, 0x0007fffb, 0x000ffff8, 0x000ffff9,
69 0x000ffffa, 0x00000000, 0x0000001a, 0x000003f8, 0x000ffffb, 0x001ffff8,
70 0x001ffff9, 0x001ffffa, 0x001ffffb, 0x003ffff8, 0x003ffff9, 0x003ffffa,
71 0x003ffffb, 0x007ffff8, 0x007ffff9, 0x007ffffa, 0x007ffffb, 0x00000000,
72 0x0000003b, 0x000003f9, 0x00fffff8, 0x00fffff9, 0x00fffffa, 0x00fffffb,
73 0x01fffff8, 0x01fffff9, 0x01fffffa, 0x01fffffb, 0x03fffff8, 0x03fffff9,
74 0x03fffffa, 0x03fffffb, 0x07fffff8, 0x00000000, 0x000003fa, 0x07fffff9,
75 0x07fffffa, 0x07fffffb, 0x0ffffff8, 0x0ffffff9, 0x0ffffffa, 0x0ffffffb,
76 0x1ffffff8, 0x1ffffff9, 0x1ffffffa, 0x1ffffffb, 0x3ffffff8, 0x3ffffff9,
77 0x3ffffffa,
78 };
79
80 static const uint8_t huffbits[] = {
81 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
82 0, 0, 0, 0, 2, 4, 5, 6, 7, 7, 7, 8,
83 8, 10, 11, 11, 11, 11, 12, 12, 2, 6, 7, 8,
84 9, 9, 12, 12, 13, 13, 13, 13, 14, 14, 14, 0,
85 3, 6, 9, 14, 15, 15, 15, 15, 16, 16, 16, 16,
86 17, 17, 17, 0, 4, 8, 9, 17, 18, 18, 18, 18,
87 19, 19, 19, 19, 20, 20, 20, 0, 5, 10, 20, 21,
88 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 0,
89 6, 10, 24, 24, 24, 24, 25, 25, 25, 25, 26, 26,
90 26, 26, 27, 0, 10, 27, 27, 27, 28, 28, 28, 28,
91 29, 29, 29, 29, 30, 30, 30,
92 };
93
94 static const uint8_t col_zag[64] = {
95 0, 8, 1, 2, 9, 16, 24, 17,
96 10, 3, 4, 11, 18, 25, 32, 40,
97 33, 26, 19, 12, 5, 6, 13, 20,
98 27, 34, 41, 48, 56, 49, 42, 35,
99 28, 21, 14, 7, 15, 22, 29, 36,
100 43, 50, 57, 58, 51, 44, 37, 30,
101 23, 31, 38, 45, 52, 59, 39, 46,
102 53, 60, 61, 54, 47, 55, 62, 63,
103 };
104
105 static av_cold int mimic_decode_init(AVCodecContext *avctx)
106 {
107 MimicContext *ctx = avctx->priv_data;
108
109 ctx->prev_index = 0;
110 ctx->cur_index = 15;
111
112 if(init_vlc(&ctx->vlc, 8, sizeof(huffbits)/sizeof(huffbits[0]),
113 huffbits, 1, 1, huffcodes, 4, 4, 0)) {
114 av_log(avctx, AV_LOG_ERROR, "error initializing vlc table\n");
115 return -1;
116 }
117 dsputil_init(&ctx->dsp, avctx);
118 ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable, col_zag);
119
120 return 0;
121 }
122
123 const static int8_t vlcdec_lookup[9][64] = {
124 { 0, },
125 { -1, 1, },
126 { -3, 3, -2, 2, },
127 { -7, 7, -6, 6, -5, 5, -4, 4, },
128 { -15, 15, -14, 14, -13, 13, -12, 12,
129 -11, 11, -10, 10, -9, 9, -8, 8, },
130 { -31, 31, -30, 30, -29, 29, -28, 28,
131 -27, 27, -26, 26, -25, 25, -24, 24,
132 -23, 23, -22, 22, -21, 21, -20, 20,
133 -19, 19, -18, 18, -17, 17, -16, 16, },
134 { -63, 63, -62, 62, -61, 61, -60, 60,
135 -59, 59, -58, 58, -57, 57, -56, 56,
136 -55, 55, -54, 54, -53, 53, -52, 52,
137 -51, 51, -50, 50, -49, 49, -48, 48,
138 -47, 47, -46, 46, -45, 45, -44, 44,
139 -43, 43, -42, 42, -41, 41, -40, 40,
140 -39, 39, -38, 38, -37, 37, -36, 36,
141 -35, 35, -34, 34, -33, 33, -32, 32, },
142 { -127, 127, -126, 126, -125, 125, -124, 124,
143 -123, 123, -122, 122, -121, 121, -120, 120,
144 -119, 119, -118, 118, -117, 117, -116, 116,
145 -115, 115, -114, 114, -113, 113, -112, 112,
146 -111, 111, -110, 110, -109, 109, -108, 108,
147 -107, 107, -106, 106, -105, 105, -104, 104,
148 -103, 103, -102, 102, -101, 101, -100, 100,
149 -99, 99, -98, 98, -97, 97, -96, 96, },
150 { -95, 95, -94, 94, -93, 93, -92, 92,
151 -91, 91, -90, 90, -89, 89, -88, 88,
152 -87, 87, -86, 86, -85, 85, -84, 84,
153 -83, 83, -82, 82, -81, 81, -80, 80,
154 -79, 79, -78, 78, -77, 77, -76, 76,
155 -75, 75, -74, 74, -73, 73, -72, 72,
156 -71, 71, -70, 70, -69, 69, -68, 68,
157 -67, 67, -66, 66, -65, 65, -64, 64, },
158 };
159
160 static int vlc_decode_block(MimicContext *ctx, int num_coeffs, int qscale)
161 {
162 DCTELEM *block = ctx->dct_block;
163 unsigned int pos;
164
165 memset(block, 0, 64 * sizeof(DCTELEM));
166
167 block[0] = get_bits(&ctx->gb, 8) << 3;
168
169 for(pos = 1; pos < num_coeffs; pos++) {
170 uint32_t vlc, num_bits;
171 int value;
172 int coeff;
173
174 vlc = get_vlc2(&ctx->gb, ctx->vlc.table, ctx->vlc.bits, 4);
175 if(!vlc) /* end-of-block code */
176 return 1;
177 if(vlc == -1)
178 return 0;
179
180 /* pos_add and num_bits are coded in the vlc code */
181 pos += vlc&15; // pos_add
182 num_bits = vlc>>4; // num_bits
183
184 if(pos >= 64)
185 return 0;
186
187 value = get_bits(&ctx->gb, num_bits);
188
189 /* FFmpeg's IDCT behaves somewhat different from the original code, so
190 * a factor of 4 was added to the input */
191
192 coeff = vlcdec_lookup[num_bits][value];
193 if(pos<3)
194 coeff <<= 4;
195 else /* TODO Use >> 10 instead of / 1001 */
196 coeff = (coeff * qscale) / 1001;
197
198 block[ctx->scantable.permutated[pos]] = coeff;
199 }
200
201 return 1;
202 }
203
204 static int decode(MimicContext *ctx, int quality, int num_coeffs,
205 int is_iframe)
206 {
207 int y, x, plane;
208
209 for(plane = 0; plane < 3; plane++) {
210 const int is_chroma = !!plane;
211 const int qscale = av_clip(10000-quality,is_chroma?1000:2000,10000)<<2;
212 const int stride = ctx->flipped_ptrs[ctx->cur_index].linesize[plane];
213 const uint8_t *src = ctx->flipped_ptrs[ctx->prev_index].data[plane];
214 uint8_t *dst = ctx->flipped_ptrs[ctx->cur_index ].data[plane];
215
216 for(y = 0; y < ctx->num_vblocks[plane]; y++) {
217 for(x = 0; x < ctx->num_hblocks[plane]; x++) {
218
219 /* Check for a change condition in the current block.
220 * - iframes always change.
221 * - Luma plane changes on get_bits1 == 0
222 * - Chroma planes change on get_bits1 == 1 */
223 if(is_iframe || get_bits1(&ctx->gb) == is_chroma) {
224
225 /* Luma planes may use a backreference from the 15 last
226 * frames preceding the previous. (get_bits1 == 1)
227 * Chroma planes don't use backreferences. */
228 if(is_chroma || is_iframe || !get_bits1(&ctx->gb)) {
229
230 if(!vlc_decode_block(ctx, num_coeffs, qscale))
231 return 0;
232 ctx->dsp.idct_put(dst, stride, ctx->dct_block);
233 } else {
234 unsigned int backref = get_bits(&ctx->gb, 4);
235 int index = (ctx->cur_index+backref)&15;
236 uint8_t *p = ctx->flipped_ptrs[index].data[0];
237
238 if(p) {
239 p += src -
240 ctx->flipped_ptrs[ctx->prev_index].data[plane];
241 ctx->dsp.put_pixels_tab[1][0](dst, p, stride, 8);
242 } else {
243 av_log(ctx->avctx, AV_LOG_ERROR,
244 "No such backreference! Buggy sample.\n");
245 }
246 }
247 } else {
248 ctx->dsp.put_pixels_tab[1][0](dst, src, stride, 8);
249 }
250 src += 8;
251 dst += 8;
252 }
253 src += (stride - ctx->num_hblocks[plane])<<3;
254 dst += (stride - ctx->num_hblocks[plane])<<3;
255 }
256 }
257
258 return 1;
259 }
260
261 /**
262 * Flip the buffer upside-down and put it in the YVU order to match the
263 * way Mimic encodes frames.
264 */
265 static void prepare_avpic(MimicContext *ctx, AVPicture *dst, AVPicture *src)
266 {
267 int i;
268 dst->data[0] = src->data[0]+( ctx->avctx->height -1)*src->linesize[0];
269 dst->data[1] = src->data[2]+((ctx->avctx->height>>1)-1)*src->linesize[2];
270 dst->data[2] = src->data[1]+((ctx->avctx->height>>1)-1)*src->linesize[1];
271 for(i = 0; i < 3; i++)
272 dst->linesize[i] = -src->linesize[i];
273 }
274
275 static int mimic_decode_frame(AVCodecContext *avctx, void *data,
276 int *data_size, const uint8_t *buf, int buf_size)
277 {
278 MimicContext *ctx = avctx->priv_data;
279 int is_pframe;
280 int width, height;
281 int quality, num_coeffs;
282 int swap_buf_size = buf_size - MIMIC_HEADER_SIZE;
283
284 /*
285 * Header structure:
286 * uint16_t I_dont_remember;
287 * uint16_t quality;
288 * uint16_t width;
289 * uint16_t height;
290 * uint32_t some_constant;
291 * uint32_t is_pframe;
292 * uint32_t num_coeffs;
293 */
294
295 if(buf_size < MIMIC_HEADER_SIZE) {
296 av_log(avctx, AV_LOG_ERROR, "insufficient data\n");
297 return -1;
298 }
299
300 width = AV_RL16(buf + 4);
301 height = AV_RL16(buf + 6);
302
303 if(!ctx->avctx) {
304 int i;
305
306 if(!(width == 160 && height == 120) &&
307 !(width == 320 && height == 240)) {
308 av_log(avctx, AV_LOG_ERROR, "invalid width/height!\n");
309 return -1;
310 }
311
312 ctx->avctx = avctx;
313 avctx->width = width;
314 avctx->height = height;
315 avctx->pix_fmt = PIX_FMT_YUV420P;
316 for(i = 0; i < 3; i++) {
317 ctx->num_vblocks[i] = -((-height) >> (3 + !!i));
318 ctx->num_hblocks[i] = width >> (3 + !!i) ;
319 }
320 } else if(width != ctx->avctx->width || height != ctx->avctx->height) {
321 av_log(avctx, AV_LOG_ERROR, "resolution changing is not supported\n");
322 return -1;
323 }
324
325 quality = AV_RL16(buf + 2);
326 is_pframe = AV_RL32(buf + 12);
327 num_coeffs = buf[16];
328
329 if(is_pframe && !ctx->buf_ptrs[ctx->prev_index].data[0]) {
330 av_log(avctx, AV_LOG_ERROR, "decoding must start with keyframe\n");
331 return -1;
332 }
333
334 ctx->buf_ptrs[ctx->cur_index].reference = 1;
335 if(avctx->get_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index])) {
336 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
337 return -1;
338 }
339
340 prepare_avpic(ctx, &ctx->flipped_ptrs[ctx->cur_index],
341 (AVPicture*) &ctx->buf_ptrs[ctx->cur_index]);
342
343 ctx->swap_buf = av_fast_realloc(ctx->swap_buf, &ctx->swap_buf_size,
344 swap_buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
345 if(!ctx->swap_buf)
346 return AVERROR_NOMEM;
347
348 ctx->dsp.bswap_buf((uint32_t*)ctx->swap_buf,
349 (const uint32_t*) (buf + MIMIC_HEADER_SIZE),
350 swap_buf_size>>2);
351 init_get_bits(&ctx->gb, ctx->swap_buf, swap_buf_size << 3);
352
353 if(!decode(ctx, quality, num_coeffs, !is_pframe)) {
354 avctx->release_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index]);
355 return -1;
356 }
357
358 ctx->buf_ptrs[ctx->cur_index].pict_type = is_pframe ? FF_P_TYPE:FF_I_TYPE;
359 *(AVFrame*)data = ctx->buf_ptrs[ctx->cur_index];
360 *data_size = sizeof(AVFrame);
361
362 ctx->prev_index = ctx->cur_index;
363 ctx->cur_index--;
364 ctx->cur_index &= 15;
365
366 /* Only release frames that aren't used for backreferences anymore */
367 if(ctx->buf_ptrs[ctx->cur_index].data[0])
368 avctx->release_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index]);
369
370 return buf_size;
371 }
372
373 static av_cold int mimic_decode_end(AVCodecContext *avctx)
374 {
375 MimicContext *ctx = avctx->priv_data;
376 int i;
377
378 av_free(ctx->swap_buf);
379 for(i = 0; i < 16; i++)
380 if(ctx->buf_ptrs[i].data[0])
381 avctx->release_buffer(avctx, &ctx->buf_ptrs[i]);
382 free_vlc(&ctx->vlc);
383
384 return 0;
385 }
386
387 AVCodec mimic_decoder = {
388 "mimic",
389 CODEC_TYPE_VIDEO,
390 CODEC_ID_MIMIC,
391 sizeof(MimicContext),
392 mimic_decode_init,
393 NULL,
394 mimic_decode_end,
395 mimic_decode_frame,
396 CODEC_CAP_DR1,
397 };